Tailpipe of automotive vehicle

ABSTRACT

A tailpipe of automotive vehicle comprises a front tube coupled to a muffler, the front tube including two flared ends and a neck having a plurality of apertures, a rear tube having a flared end, an outer venturi tube surrounded a rear portion of the front tube and the whole rear tube, the outer tube including a flared front end, a cylindrical section, an enlarged section, and a rear section having an inward extending rim at an opening thereof, and a plurality of twisted blades equally spaced apart around the rear tube and connected to the front, the rear, and the outer tubes, each blade having a plurality of apertures. Stream of exhaust from the muffler entering into the neck is divided into a number of components prior to forming whirlwind after leaving the tailpipe.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to tailpipe of automotive vehicle and moreparticularly to such a tailpipe of automotive vehicle with improvedcharacteristics.

2. Description of Related Art

A conventional exhaust pipe of an internal combustion engine comprisesan expansion chamber, a resonant chamber at the rear of the expansionchamber, and a plurality of perforated pipes disposed in both chambers,each pipe being enclosed by glass fibers or sound-absorbing material forsilencing noise. Exhaust from the engine may flow into the chambersthrough apertures of the pipes. This can build a back pressure in thechambers, resulting in a partial back flow of exhaust into the engine.As an end, output torque of the engine is lowered due to incompletecombustion of the engine. U.S. Pat. No. 4,792,014 discloses anexcessively long tailpipe of internal combustion engine such that itcannot be readily mounted at the exhaust pipe. Instead, a modificationof the existing exhaust pipe is required. This is not advantageous.Further, noise is serious when a car incorporated such tailpipe isdriving at high speed, especially more than 100 km per hour. Hence, aneed for improvement exists.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a tailpipe ofautomotive vehicle. The tailpipe has a reduced length so as to bereadily mounted at an exhaust pipe. The tailpipe comprises an outer tubeconstructed by incorporating the principles of venturi tube. Byutilizing the present invention, it is possible of carrying out a morecomplete combustion, reducing air pollution, and further silencingnoise.

To achieve the above and other objects, the present invention provides atailpipe of an automotive vehicle, comprising a front tube including twoflared ends and an intermediate neck having a plurality of rows ofapertures wherein one flared end of the front tube is coupled to amuffler; a rear tube having a flared end; an outer tube surrounded arear portion of the front tube and the whole rear tube, the outer tubeincluding a flared front end, a cylindrical section, an enlargedsection, and a rear section having an inward extending rim at an openingthereof; and a plurality of twisted blades equally spaced apart aroundthe rear tube and connected to the front, the rear, and the outer tubes,each blade having a plurality of apertures, wherein a stream of exhaustfrom the muffler entering into the neck is divided into a firstcomponent flowing through the rear tube, and a second component flowinginto a space between the neck and the outer tube through the apertures,the second component is mixed with air drawn from the front end of theouter tube to form a third component, the third component flows to arear of the outer tube after being baffled by the blades and passing aplurality of channels each between two adjacent blades to form a fourthcomponent in a form of whirlwind, and a fifth component in a form ofwhirlwind is formed by mixing the fourth component with the firstcomponent after leaving the tailpipe.

In one aspect of the present invention the outer tube has a length ofabout 12 cm, the front tube has a length of about 12.5 cm, and thetailpipe has a length of about 20 cm.

In another aspect of the present invention there is further provided amember formed of sound-absorbing material on a cylindrical surface ofthe outer tube.

The above and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptiontaken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a preferred embodiment of tailpipe ofautomotive vehicle according to the invention;

FIG. 2 is a front view of the tailpipe;

FIG. 3 is a rear view of the tailpipe;

FIG. 4 is a perspective view of the tailpipe; and

FIG. 5 is a view similar to FIG. 1 for illustrating a stream of exhaustthrough the tailpipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 to 4, there is shown a tailpipe of an automotivevehicle constructed in accordance with the invention. The tailpipecomprises a front tube 1, an outer tube 2, a rear tube 3, and aplurality of twisted blades 4. Each component will be described indetail below.

The front tube 1 comprises a front section 10, a coupling 11 at thefront section 10, the coupling 11 having a plurality of lengthwise slits111 and a ring fastener 112 enclosed the coupling 11 for flexiblycompressing the coupling 11 and fastening one end of a muffler S at thecoupling 11, a flared rear section 13, and a neck 12 interconnected thefront section 10 and the rear section 13, the neck 12 having a pluralityof rows of apertures 14 on its surface.

The rear tube 3 comprises a front section 32 coupled to the rear section13, an intermediate section 31 having a diameter slightly smaller thanthat of the front tube 1, and a flared rear section 33.

A rear portion of the front tube 1 and the whole rear tube 3 aresurrounded by the outer tube 2. The outer tube 2 is constructed byincorporating the principles of venturi tube. The outer tube 2 comprisesa flared front section 21, a cylindrical section 20, an enlarged section22, a rear section 24, and an inward extending rim 23 at the opening ofthe rear section 24.

The blades 4 are equally spaced apart around the intermediate section 31and are extended therefrom to fixedly couple to an inner surface of theenlarged section 22. The blade 4 comprises a front section 41 fixedlyconnected to the rear section 13, a plurality of apertures 42, and arear section 43 coupled to rear portions of the outer tube 2 and therear tube 3.

Referring to FIG. 5, stream of exhaust from an operating internalcombustion engine to the tailpipe via an exhaust pipe will be describedin detailed below. Stream of exhaust E enters into the neck 12 afterleaving the muffler S. At the neck 12, pressure of the stream of exhaustE decreases in which a portion (i.e., stream component E1) of the streamof exhaust E flows into a space between the neck 12 and the cylindricalsection 20 through the apertures 14. Stream component E1 is then mixedwith air A drawn from the front section 21. Also, pressure of the streamcomponent E1 decreases. Another portion (i.e., stream component E2) ofthe stream of exhaust E flows out of the rear section 13 into a spacebetween the intermediate section 31 and the enlarged section 22 to bebaffled by the blades 4. After leaving the blades 4 by passing aplurality of channels each between two adjacent blades 4 and theapertures 42, a whirlwind is formed. Still another portion (i.e., streamcomponent E3) of the stream of exhaust E flows into the rear tube 3.Also, pressure of stream component E3 decreases in the rear tube 3.Thus, a stream component E4 is formed after leaving the rear section 33.A whirlwind type of stream component E5 is formed by the mixture ofstream component E4 and stream component E2. As an end, exhaust E0 iscarried away by stream component E5. Note that the provision ofapertures 14 and 42 can reduce both temperature and pressure of exhaust.

Preferably, the outer tube 2 has a length of about 12 cm, the front tube1 has a length of about 12.5 cm, and the tailpipe has a length of about20 cm less than prior art. Hence, the tailpipe can be readily mounted atthe rear of muffler S of an automotive vehicle at the coupling 11.Moreover, a sound-absorbing material can be formed around the outer tube2 for further silencing noise.

It will be evident from the foregoing that the invention has thefollowing advantages: High pressure exhaust from the muffler can beeffectively driven out of the tailpipe by inducting air into thetailpipe to mix with stream of exhaust. As such, a more completecombustion of the engine is made possible. Further, pollutant containedin the exhaust can be effectively diluted by the induction or air.Hence, exhaust leaving the tailpipe is found to comply with even thestrictest emission standard. Pressure of exhaust leaving the tailpipe issufficiently lowered by the provision of a number of continuous enlargedand constricted stages of the tailpipe by incorporating the principlesof venturi tube. This further facilitates the emission of exhaust.

While the invention herein disclosed has been described by means ofspecific embodiments, numerous modifications and variations could bemade thereto by those skilled in the art without departing from thescope and spirit of the invention set forth in the claims.

1. A tailpipe of an automotive vehicle, comprising: a front tubeincluding two flared ends and an intermediate neck having a plurality ofrows of apertures wherein one flared end of the front tube is coupled toa muffler; a rear tube having a flared end; an outer tube surrounded arear portion of the front tube and the whole rear tube, the outer tubeincluding a flared front end, a cylindrical section, an enlargedsection, and a rear section having an inward extending rim at an openingthereof; and a plurality of twisted blades equally spaced apart aroundthe rear tube and connected to the front, the rear, and the outer tubes,wherein a stream of exhaust from the muffler entering into the neck isdivided into a first component flowing through the rear tube, and asecond component flowing into a space between the neck and the outertube through the apertures, the second component is mixed with air drawnfrom the front end of the outer tube to form a third component, thethird component flows to a rear of the outer tube after being baffled bythe blades and passing a plurality of channels each between two adjacentblades to form a fourth component in a form of whirlwind, and a fifthcomponent in a form of whirlwind is formed by mixing the fourthcomponent with the first component after leaving the tailpipe.
 2. Thetailpipe of claim 1, wherein one flared end of the front tube comprisesa plurality of lengthwise slits.
 3. The tailpipe of claim 1, whereineach blade comprises a plurality of apertures.
 4. The tailpipe of claim1, wherein the outer tube has a length of about 12 cm.
 5. The tailpipeof claim 1, wherein the front tube has a length of about 12.5 cm.
 6. Thetailpipe of claim 1, wherein the tailpipe has a length of about 20 cm.7. The tailpipe of claim 1, further comprising a member formed ofsound-absorbing material on a cylindrical surface of the outer tube.